Cascade water cooler aerator-multiplyer

ABSTRACT

An apparatus for cooling a blast furnace lining wherein a plurality of water jets are directed onto an aerator-multiplyer circumferentially attached to said furnace. Said aeratormultiplyer having a plurality of porous sheet surfaces to collect, aerate and direct the water evenly onto the furnace shell.

United States Patent Hopkins 5] July 15, 1975 4] CASCADE WATER COOLER 3,845,813 11/1914 Bougard l 266/32 x AERATOR-MULTIPLYER [75] ln e t r Jay R- N-K s, Provo. Utah Primary Examiner-Gerald A. Dost [73] Assignee: United States Steel Corporation, Attorney Agem or Firm-Forest Sexton Pittsburgh, Pa.

22 F l 29, 9 1 1 74 57 ABSTRACT [2]] Appl. No.: 518,540

An apparatus for cooling a blast furnace lining [52] U S Cl 266/32 wherein a plurality of water jets are directed onto an [5]] 7/10 aerator-multiplyer circumferentially attached to said [58] Fieid 432/238 furnace. Said aerator-multiplyer having a plurality of porous sheet surfaces to collect, aerate and direct the [56] Reierences Cited water evenly onto the furnace shell.

UNITED STATES PATENTS 11 Claims, 5 Drawing Figures 2,711,3l l 6/l955 Afileck et al. 266/32 CASCADE WATER COOLER AERATOR-MULTIPLYER BACKGROUND OF THE INVENTION One of the major cost items in any iron producing blast furnace is the refractory brick lining. Hence, considerable effort is expended in cooling the furnace structure to optimize lining life, particularly in the lower portions thereof, i.e., bosh and hearth portions, where higher temperatures prevail.

One well known practice for cooling the bosh portion of a blast furnace is to provide a continuous cascading water flow over the outer shell in contact with the bosh lining. This is usually done by providing an annular water manifold around the bosh and spaced slightly away therefrom just below the mantle. A large number of evenly spaced nozzles are provided around the inside of the manifold to direct closely spaced streams of water against the bosh shell. The water thus spreads over the shall and cascades downward by the force of gravity to cool the bosh. Although this is sufficiently effective in that it is practiced in commercial mills, there are considerable problems associated therewith in keeping an even and effective flow of water over the bosh shell, particuarly in view of the fact that the bosh shell wall is inwardly sloping. Specifically, the water pressure, upon emerging from the nozzles must be minimized in order to prevent excessive splashing whereby the water bounces away from the shell rather than adhering thereto. In addition, uneven water film thicknesses cascading downward on the bosh shell surface will tend to agglomerate by action of surface tension and hence drop off of the shell surface. These problems are aggravated by the fact that the nozzle openings will tend to plug due to the low water pressure further contributing to uneven water flow. Hence, despite constant attention to the cooling apparatus, hot spots do develop in the bosh which shortens the life of the lining therein.

SUMMARY OF THE INVENTION This invention is predicated upon my conception and development of a simple and inexpensive aeratormultiplyer fabricated from simple wire screen which is designed to improve the cooling characteristics of eascading water on a blast furnace bosh.

Accordingly, an object of this invention is to provide a simple and inexpensive means for improving the cooling characteristics of cascading water on a blast furnace bosh sectionv Another object of this invention is to provide a simple wire screen aerator-multiplyer to be used in combination with a conventional cascading water cooling system for cooling a blast furnace bosh section to improve the cooling characteristics thereof.

A further object of this invention is to provide a simple wire screen aerator-multiplyer to be used in combination with a conventional cascading water cooling system for cooling a blast furnace bosh section which provides a heavier and more uniform water flow over the bosh outer shell.

Still another object of this invention is to provide a simple wire screen aerator-multiplyer for improving the cooling effect of any cascading water cooling system.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partial section view through one wall of a blast furnace bosh section and the encircling water manifold showing the water spray system in operation according to prior art practice.

FIG. 2 is a partial elevation of the system shown in FIGv 1.

FIG. 3 is identical to FIG. 1 except that the aeratormultiplyer of this invention is shown in place.

FIG. 4 is a partial elevation of the system shown in FIG. 3.

FIG. 5 is a section view of an aerator-multiplyer according to one embodiment of this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to better understand the advantages of this invention, it is helpful to understand the disadvantages of the prior art. Accordingly. reference to FIGS. 1 and 2 will illustrate the prior art system of cooling a blast furnace bosh section with cascading water wherein the blast furnace bosh lining 10 and adjacent shell 12 are cooled by a large number of water jets l4 emerging from a spray header 16 through nozzles 18. The velocity and pressure of water jets 14 must be minimized in order to prevent or minimize splashing as the water strikes shell 12. The thickness of the water film running down the face of shell 12 can usually be maximized to I/I6- to 3/32-inch without water dropping off vertically downward. In FIG. 2 it can be seen that water jets I4 strike shell 12 in a spaced relationship, and that the eascading water running down the face of shell 12 from each jet l4 gently spreads laterally and eventually merges with cascading water from adjacent jets, The net result of this flow pattern is that the upper portion of the bosh is not uniformly cooled since the cooling water does not reach those areas of the shell 12 between jets l4 above the point where the individual water flows merge together.

In accordance with one embodiment of this invention the cooling efficiency of the above described cooling system is increased 4 to 5 times by placing a simple aerator-multiplycr 20 around the blast furnace bosh at the line where the water jets l4 impinge so that the water will impinge onto the aerator-multiplycr 20. The aerator-multiplyer 20 consists of a plurality of porous sheet surfaces which aerates, and more evenly distributes the water onto the surface of shell 12. In the embodiment shown, aerator-multiplyer 20 is fabricated from a strip of wire screen whereby the plurality of sheet surfaces are provided by horizontal folds in the screen. Although many suitable configurations could be formed, one well proven form is to fold the screen into a triangular cross-section as shown in FIG. 5, wherein an upper horizontal surface 22 is provided to receive the impact of water jets I4, and the inclined side surface 24 is intended for direct contact with the surface of shell 12. The triangular form is completed by the outer surface 26, while a plurality of inside surfaces 28 are provided between surfaces 24 and 26, with the lower edges of surfaces 26 and 28 at or near the surface of shell 12. Surfaces 26 and 28 are intended to catch any water falling through porous surface 22 and direct that water to the surface of shell 12.

The above described aerator-multiplyer 20 is preferably fabricated into a plurality of arcuate sections which are then placed end'to-end around the blast furnace bosh. The arcuate sections can be held in place by any suitable means such as for example pins or nails 30 welded onto the face of shell I2.

Reference to FIGS. 3 and 4 will illustrate the operation of the above described embodiment of this invention. As in the prior art system, a large number of water jets 14 are emitted from a spray manifold 16 through nozzles 18. In this case however, the water jets 14 do not directly impinge onto shell 12, but rather impinge onto aeratonrnultiplyer 20, preferably on the upper surface 22 thereof. Since surface 22 is a porous wire screen, the water jets 14 are aerated and broken up with some of the water flowing along the surfaces of the individual wires to surface 24 and hence onto the surface of shell 12, while the balance of the water passes through the porous surface 22 and onto the porous surface 26 and 28 therebelow. Since surfaces 26 and 28 are inclined towards shell 12, this water too ultimately flows onto shell 12. Accordingly, the several porous surfaces of aerator-multiplyer 20 will collect most of, if not all of the sprayed water and deposit it in aerated form onto shell 12. As illustrated in FIG. 4, aeratormultiplyer 20 causes the sprayed water to spred laterally more quickly, thus greatly minimizing the unwetted areas between water jets 14 (contrast to FIG. 2). More surprising however, is the fact that the aeratormultiplyer 20 will not only provide a more uniform water film on shell [2, but will permit an increase in the amount of sprayed water of 4 to times greater, with the water film thickness maximized at about /s-inch without water dropping therefrom. Contrast this to the maximum prior art thickness of about 3/32-inch. Accordingly. since the water volume at nozzles 18 can be increased 4 to 5 fold, there is a lesser tendency for nozzles 18 to plug. and even if some nozzles 18 do become plugged. the aerator-multiplyer 20 will provide better lateral distribution of the water at shell 12 so that the adverse affect thereof is minimized.

In order to better illustrate the advantages of this in vention it is noted that the above described embodiment was tested on a commercial producing blast fur nace. The aeratonmultiplyer 20 was fabricated from A-lllCl'l galvanized steel wire screen folded into a crosssectional configuration as shown in FlG. 5, in a plurality of arcuate sections 3 feet long. In addition, a plurality of Via-inch diameter nails 30 were welded around shell 12 on about 18-inch centers. The aeratormultiplyer sections were then impaled onto the nails 30 and held tightly against shell 12 with large washers (not shown) tightly fit over nails 30.

In operation, the advantages as described above were realized. Namely, the aerator-multiplyer 20 attached substantially as shown in FIGS 3 and 4 permitted a 4 to 5 fold increase in water emitted through nozzles 18 without significant splashing or drop-off. As a result, water film thicknesses cascading down the surface of shell 12 were easily maintained at from /s to %inch with a resulting substantial increase in cooling efficiency. Although it was difficult to numerically measure cooling efficiency, use of the above described embodiment with the increased water flow, has permitted the use of cheaper carbon brick in the furnace bosh section with a life span at least equal to that of the more expensive ceramic brick normally used and cooled by prior art methods, and has further reduced unschcd uled furnace outages.

Although only one specific embodiment of this invention has been described. it is obvious that other forms could be utilized to effect the same end. For example, the porous sheet surfaces could be formed from materials other than wire screen, e.g., sheet metal hav ing a large number of small holes punched therethrough, or even nonmetallic materials such as woven fiber glass or asbestos. Obviously, the configuration of the various porous sheet surfaces can be greatly varied, although it is obvious that such surfaces should be somewhat pivotally spaced from each other so that the lower edge of each will deposit its water onto shell 12 or onto another sheet surface, the idea being of course to direct all the water inward towards shell 12 to be eventually deposited thereon. In addition, it is obvious that this invention could be used to cool surfaces other than blast furnace surfaces where at least one water jet is directed thereagainst. The advantages are of course best realized when such surfaces to be cooled are sub stantially vertical where heavy water films thereon are difficult to maintain.

I claim:

1. In an apparatus for cooling a substantially vertical hot surface wherein at least one jet of water is directed against said hot surface so that the water therefrom will run down said hot surface and cool the same, the improvement comprising, an aerator-multiplyer having a plurality of porous sheet surfaces attached to said hot surface such that the water jet is directed onto said aerator-multiplyer and the porous sheet surfaces thereof more evenly distributes the water onto said hot surface, and allows a greater flow of water on the hot surface without drop-off.

2. An apparatus according to claim 1 in which a plurality of water jets are directed onto said aeratormultiplyer.

3. An apparatus according to claim 1 in which said porous sheet surfaces consist of metallic wire screen.

4. An apparatus according to claim 1 in which said porous sheet surfaces define a substantially triangular cross-section, said porous surfaces spaced apart along the top edges thereof and the bottom edges converged together at the hot surface.

5. An apparatus according to claim 1 in which said porous sheet surfaces are formed from a single sheet of porous material folded to define the individual porous sheet surfaces.

6. An apparatus according to claim 5 in which said single sheet of porous material is folded to define a substantially triangular cross-section with one surface thereof disposed against the hot surface.

7. In an apparatus for cooling blast furnace lining wherein said lining is supported against an outer shell structure and a plurality of water jets are directed against said shell so that the water therefrom will run down the surface of said shell to cool the shell and adja cent furnace lining the improvement comprising an aerator-multiplyer having a plurality of porous sheet surfaces attached to said shell such that the water jets are directed onto said aerator-multiplyer and the porous sheet surfaces thereof evenly distribute the water onto the shell, and allows a greater flow of water on the shell without dropoff.

8. An apparatus according to claim 7 in which said porous sheet surfaces consist of metallic wire screen.

9. An apparatus according to claim 7 in which said porous sheet surfaces define a substantially triangular cross-section, said porous surfaces spaced apart along the top edges thereof and the bottom edges converged together at the hot surfaces.

3,894,726 6 10. An apparatus according to claim 7 in which said single sheet of porous material is folded to define a subporous sheet Surfaces are formed from a single Sheet of stantially triangular cross-section with one surface porous material folded to define the individual porous sheet surfaces.

11. An apparatus according to claim 10 in which said 5 thereof disposed against the hot surface.

* i I) t 

1. In an apparatus for cooling a substantially vertical hot surface wherein at least one jet of water is directed against said hot surface so that the water therefrom will run down said hot surface and cool the same, the improvement comprising, an aerator-multiplyer having a plurality of porous sheet surfaces attached to said hot surface such that the water jet is directed onto said aerator-multiplyer and the porous sheet surfaces thereof more evenly distributes the water onto said hot surface, and allows a greater flow of water on the hot surface without drop-off.
 2. An apparatus according to claim 1 in which a plurality of water jets are directed onto said aerator-multiplyer.
 3. An apparatus according to claim 1 in which said porous sheet surfaces consist of metallic wire screen.
 4. An apparatus according to claim 1 in which said porous sheet surfaces define a substantially triangular cross-section, said porous surfaces spaced apart along the top edges thereof and the bottom edges converged together at the hot surface.
 5. An apparatus according to claim 1 in which said porous sheet surfaces are formed from a single sheet of porous material folded to define the individual porous sheet surfaces.
 6. An apparatus according to claim 5 in which said single sheet of porous material is folded to define a substantially triangular cross-section with one surface thereof disposed against the hot surface.
 7. In an apparatus for cooling blast furnace lining wherein said lining is supported against an outer shell structure and a plurality of water jets are directed against said shell so that the water therefrom will run down the surface of said shell to cool the shell and adjacent furnace lining the improvement comprising an aerator-multiplyer having a plurality of porous sheet surfaces attached to said shell such that the water jets are directed onto said aerator-multiplyer and the porous sheet surfaces thereof evenly distribute the water onto the shell, and allows a greater flow of water on the shell without drop-off.
 8. An apparatus according to claim 7 in which said porous sheet surfaces consist of metallic wire screen.
 9. An apparatus according to claim 7 in which said porous sheet surfaces define a substantially triangular cross-section, said porous surfaces spaced apart along the top edges thereof and the bottom edges converged together at the hot surfaces.
 10. An apparatus according to claim 7 in which said porous sheet surfaces are formed from a single sheet of porous material folded to define the individual porous sheet surfaces.
 11. An apparatus according to claim 10 in which said single sheet of porous material is folded to define a substantially triangular cross-section with one surface thereof disposed against the hot surface. 